Logan, a 53-year-old investment banker, leads a tour of his house in the Marin County town of Tiburon, perched above the San Francisco Bay. The eclectically furnished, art-packed living room sets the tone. On one side of the room, Untitled (Venus/The Great Circle) by Jean-Michel Basquiat hangs catercorner to David Park's brooding canvas The Bathers. Across the way, Andy Warhol's Double Jackie faces off against The Room, a whimsical Philip Guston. There's a ravishing, newly purchased early Hockney, Seated Woman Being Served Tea, in the dining room, and looming above a stairwell is Gottfried Helnwein's powerful Untitled (Child).

untitled (blue child)

oil and acrylic on canvas, 1994

As collectors, Kent and Vicki Logan operate like stealth bombers. They only began buying art less than five years ago, and have since disconcerted more than a few dealers by turning up at their galleries unannounced and, over time, dropping millions of dollars. "Anthony d'Offay is by far our biggest dealer," Kent says. "I was a walk-in without a referral."

Based in northern California, the Logans first came to public attention last fall, when they donated $1.5 million to the San Francisco Museum of Modern Art and an equal amount to the California College of Arts and Crafts. They also gave the museum a fractional gift -- which will be on view in an exhibition opening in September -- of what curator Gary Garrels describes as "one of the most exciting and important collections of contemporary art being formed in the United States today." After 2012, the museum will own the 250-plus works in the Logan collection outright.

Logan, a 53-year-old investment banker, leads a tour of his house in the Marin County town of Tiburon, perched above the San Francisco Bay. The eclectically furnished, art-packed living room sets the tone. On one side of the room, Untitled (Venus/The Great Circle) by Jean-Michel Basquiat hangs catercorner to David Park's brooding canvas The Bathers. Across the way, Andy Warhol's Double Jackie faces off against The Room, a whimsical Philip Guston. There's a ravishing, newly purchased early Hockney, Seated Woman Being Served Tea, in the dining room, and looming above a stairwell is Gottfried Helnwein's powerful Untitled (Child).

Initially, the Logans wanted to gather only contemporary art. "The great collections have been assembled when the work was being created," Logan says, citing the famous 1960s-era Scull collection as an example. "They had lots of Warhols long before it was clear that Warhol would sell for millions." But the Logans -- who own plenty of Warhols themselves, including Self-portrait, Brillo Boxes, and Electric Chair -- then decided to include earlier periods, as well, to reflect influences on today's art. "We're trying to find artists who affected subsequent generations of artists."

Just a few years ago, Logan had retired early from a brokerage firm and was living in Greenwich, Connecticut. Then he took a job at Nations Bank Montgomery Securities in the Bay Area. He began to collect, in part because, the San Francisco art scene seemed less intimidating. "It's easier to start here than it is in New York," he says. He bought his first four paintings -- including Wayne Thiebaud's Bright City -- from Campbell-Thiebaud in San Francisco in 1993 and continues to buy work by Bay Area artists.

Giving the art to the San Francisco Museum of Modern Art was an obvious choice. Logan says, "It's an important museum, but it's still at a point where the collection could make a difference." If all goes well, the collection will help in other ways too. "We want to really be a patron for young emerging artist's, to give them support and a showcase. You'll come to see the Warhols the Polkes, but you'll see the Kevin Christisons, too."